a) Field of the Invention
The present invention relates to a method for automatic continuous changing of cartridge-type magnetic tapes, and more particularly to a method for automatic continuous changing of cartridge-type magnetic tapes, which is suitable for use in continuously repeating the loading of a cartridge-type magnetic tape into a magnetic tape unit provided with an automatic threading facility and with which the automatic cartridge-type magnetic tape changer is used, and reception of the cartridge-type magnetic tape unloaded from the magnetic tape unit.
b) Description of the Related Art
With conventional automatic cartridge-type magnetic tape changers, a plurality of cartridge-type magnetic tapes (will be referred to as "cartridges" hereinafter) is set in a magazine. An object one of the cartridges is positioned in a cartridge inlet/outlet, and then loaded into a magnetic tape unit (will be referred to as "MT unit" hereinafter). After data-processing in the MT unit, the cartridge is unloaded from the latter and received again into the magazine. All these operations are automatically done.
One such automatic cartridge changer is disclosed in Japanese Unexamined Utility Model Publication (Kokai) No. 61-79856. In this automatic cartridge changer, for replacing the cartridges already data-processed in the MT unit with those yet to be data-processed in the MT unit, the magazine must be removed from the automatic cartridge changer. Therefore, in case the operator of such a conventional automatic cartridge changer wants to replace the data-processed cartridges in the magazine with cartridges yet to be data-processed, he must wait until all of the cartridges in the magazine have been data-processed. Otherwise, after the data processing of a cartridge currently loaded in the MT unit finishes, the operator must dismount the magazine interrupting the loading and data processing of a next cartridge, and replace a cartridge or cartridges already data-processed with a new cartridge or cartridges' the data of which he wants to process. Hence, the operator is compelled to perform troublesome tasks so that it takes a long time to replace the cartridges.
The disadvantages of and problems with the conventional techniques will be described in further detail. Assume for example that the magazine is designed to receive eight cartridges and that eight cartridges yet to be data-processed are initially set in the magazine. When the automatic cartridge changer has completed the data-processing handling of first the four, for example, among the eight cartridges yet to be data-processed, the operator interrupts the automatic cartridge changer and dismounts the magazine from the automatic cartridge changer. Further, he removes the data-processed four cartridges from the magazine, and sets into the magazine four fresh cartridges yet to be data-processed. Then, he sets the magazine into the automatic cartridge changer. Next, he starts the automatic cartridge changer for data-processing operations. In this case, the automatic cartridge changer will continuously effect the loading and reception for the four fresh cartridges set in the magazine and yet to be data-processed as well as for the cartridges initially set in the magazine. Therefore, after dismounting the cartridge from the automatic cartridge changer, he has to replace the fresh cartridges yet to be data-processed with the data-processed cartridges and remember the number of the cartridges which are to be replaced until he finishes the data processing task. Therefore, he is compelled to do troublesome and complicated operations with the automatic cartridge changer and he may also fail in such operations.